the amount of carbon dioxide reaching the atmosphere. it is man kind and his activities which are changing the environment of our planet and damaging in dangerous ways. change to the sea around us, change to the atmosphere above, leading in turn to change in the world's climate, which could alter the way we live in the most fundamental way of all. that prospect is a new factor in human affairs. it's comparable in implications to the discovery how to split the atom. indeed, it results could be more far reaching. we can't just do nothing. >> one of the key arguments that